Only getting an empty file.

Question

I know that my propertiesSystem object has stuff in it because I can see it on the Eclipse Console, but I cannot figure out why it won't write the information to the SystemProperties.txt file.
Properties propertiesSystem = new Properties();
propertiesSystem = System.getProperties();
System.out.println(propertiesSystem.toString());
propertiesSystem.list(new PrintWriter("SystemProperties.txt"));Please tell me I haven't made some really simple mistake.

Answer 1

Okay, now I know what I did wrong. Forgot to close the Print Writer. [Slaps forehead] Here's my new code:
Properties propertiesSystem = new Properties();
propertiesSystem = System.getProperties();
File fileProperties = new File("SystemProperties.txt");
PrintWriter writerOut = new PrintWriter(new BufferedWriter(new FileWriter(fileProperties)));
writerOut.println(propertiesSystem);
writerOut.close();
That works. Although it does raise a question: If I decide to do the whole operation on one line, as I did originally, creating a new PrintWriter within the list method, how do I close that PrintWriter?